High temperature resistant polychloroprene adhesive resin

ABSTRACT

Superior polychloroprene adehsives are prepared by incorporating the reaction product of an alkali catalyzed alkyl phenol-formaldehyde resin and zinc resinate. Preferably an arylphenol and/or bisphenol A is also incorporated. Also preferably rosin is included in the composition. Other zinc compounds, e.g. zinc oxide, zinc borate, zinc phosphate, zinc carbonate, and zinc salicylate can be used in place of zinc resinate.

This application is a continuation in part of application 873,059 filedOct. 31, 1969, now abandoned.

The present invention relates to neoprene adhesives.

It is an object of the invention to improve the properties of neopreneadhesives.

Another object is to increase the peel and shear stress resistance ofneoprene adhesives at elevated temperatures.

Still further objects and the entire scope of applicability of thepresent invention will become apparent from the detailed descriptiongiven hereinafter; it should be understood, however, that the detaileddescription and specific examples, while indicating preferredembodiments of the invention, are given by way of illustration only,since various changes and modifications within the spirit and scope ofthe invention will become apparent to those skilled in the art from thisdetailed description.

It has now been found that these objects can be attained by preparing anadhesive cement containing polychloroprene (neoprene) and the reactionproduct of an alkali catalyzed alkylphenol and/or arylphenolformaldehyde resin and zinc resinate. Rosin is preferably added as aprocessing aid and does not interfere with the excellent hightemperature adhesion developed in neoprene adhesives utilizing the zincresinate modified alkylphenol-formaldehyde resin of the presentinvention. There is also preferably employed a chlorophenol orarylphenol, e.g. p-phenylphenol, p-tolyphenol or alpha methyl styrylphenol and/or Bisphenol A as modifiers for the alkylphenol. The arylphenol can be used by itself without an alkylphenol.

The alkylphenol is preferably a para substituted phenol in which thesubstituent is an alkyl group of 2 to 6 carbon atoms. The parasubstituted phenol is preferably p-t-butyl phenol but there can beemployed p-t-amyl phenol, p-hexyl phenol, p-n-butyl phenol, p-cyclohexylphenol, p-ethyl phenol, p-isopropyl phenol.

It has further been found that in place of zinc resinate in preparingthe resins for incorporation into polychloroprene adhesives there can beused other zinc compounds such as zinc oxide, zinc carbonate, zincborate, zinc salicylate and zinc phosphate for example. These resinsimpart exceptional properties to the polychloroprene adhesives inrespect to high heat resistance.

There can be used as little as 0.3 mole of formaldehyde per mole ofalkyl phenol or the like. Frequently there is employed 0.7 mole offormaldehyde and preferably 0.9 to 1.8 moles of formaldehyde areemployed per mole of phenol.

The Bisphenol A (2,2-bis-(4'-hydroxyphenyl) propane) when employed isused in an amount of 2 to 8% based on the total phenols reacted.

When a chlorophenol or an arylphenol is employed in addition to thealkylphenol, it is employed in an amount of 5 to 70% of the totalphenols.

The catalyst employed in forming the alkyl (or aryl) phenol formaldehyderesin is alkaline. There can be used any alkaline catalystconventionally employed for such purpose, e.g. alkali metal hydroxidessuch as sodium hydroxide and potassium hydroxide, alkaline earth metaloxides and hydroxides, e.g., calcium oxide, calcium hydroxide, bariumhydroxide and magnesium oxide, alkali carbonates, e.g. sodium carbonateand potassium carbonate, ammonium hydroxide, quaternary ammoniumhydroxides, anion exchange resins, basic amines, e.g. triethanolamine.

The alkaline material can be neutralized with any conventional acid,e.g. hydrochloric acid, hydrobromic acid, oxalic acid, chloroaceticacid, phosphoric acid, etc.

The order of reacting the phenol, formaldehyde and zinc resinate orother source of zinc is not critical. The zinc resinate or other sourceof zinc is normally used in an amount of 5 to 75%, frequently 5 to 35%and most often in an amount of 7.6 to 18% based on the final resin. Aslittle as 1% of zinc compound can be employed. The reaction with thezinc resinate or other source of zinc is carried out with heat usuallyterminating at 150 to 250° C. although other temperatures can be used.When rosin is employed, it is usually used in an amount of 20 to 45% ofthe phenols employed but can be used in lesser amounts down to zero.

The alkaline catalyzed phenol-formaldehyde resin is preferably from 60to 90% of the total final resin.

Unless otherwise indicated, all parts and percentages are by weight.

While in the specific examples there was employed Neoprene AC (anonsulfur modified chloroprene polymer stabilized with thiuramdisulfide) there can be used other commercially available neoprenes suchas Neoprene Type CG, Neoprene Type AD, Neoprene Type GN, and Neoprene W.These various neoprenes are described in Kell Patent 3,242,113.

There is employed 5 to 200 parts of the zinc resinate or other zinccompound reacted phenolic resin per 100 parts of neoprene(polychloroprene).

The adhesive cement also contains a volatile organic solvent. Thissolvent can be toluene, ethyl acetate, trichloroethylene, methyl ethylketone, hexane, acetone, benzene or mixtures of these materials.Suitable solvent mixtures for example are shown in the Garrett patent3,185,658 column 3, lines 3-39.

There can also be included in the adhesive cement conventional neopreneadditives such as zinc oxide and magnesium oxide and antioxidants suchas Zalba-special (a hindered phenol composition coming within thedisclosure and claims of U.S. Pat. No. 2,999,841 and made of 45%hindered phenol, 45% sorbitol and 10% Microcell B (calcium silicate) thehindered phenol being largely 2,6-di-t-butyl-p-phenyl phenol withsmaller amounts of isomeric impurities and a small amount of2,4'6-tri-t-butyl phenyl phenol) and other hindered phenols, e.g.2,6-di-t-butyl-4-phenylphenol, p-methyl-o-t.-butyl methylene bis-phenol,2,2'-methylenebis (4-methyl-6-t-butyl phenol), as well as amines, e.g.Neozone D (N-phenyl-B-naphthylamine) N-phenyl a-naphthylamine, etc.

EXAMPLE 1

900 grams of xylene, 15.6 grams of Bisphenol A, 283 grams ofp-phenylphenol, 500 grams of p-t-butyl phenol, 50 grams of methanol and529 grams of 37% aqueous formaldehyde were loaded into a glass flask setup for atmospheric reflux. The mixture was heated to 55° C., then 75grams of 50% aqueous sodium hydroxide was added and the batch wasbrought to reflux and held for 45 minutes. The reaction mixture was thencooled by adding 500 grams of water. The pH of the resin was thenbrought to 1 by the addition of 165-170 grams of 20% aqueoushydrochloric acid. The neutralized condensate was agitated for a while,then the layers were allowed to separate. The water layer was decantedand the resin was washed twice more with 500 parts each time of water toremove sodium chloride.

The flask was then set up for distillation and there were added 285grams of wood rosin and 9 grams of 85% phosphoric acid. The resin wasdistilled at atmospheric pressure to approximately 150° C. There werethen added 135 grams of Unirez 1028 (zinc resinate) and distillation wascontinued to 215° C. Full vacuum was applied and the distillation wascontinued to 225° C. The resin was then poured out of the flask to cool.The yield was 1260 grams, M.P. 315° F., molecular weight, 1705.

This thermoplastic resin developed in neoprene adhesives extraordinaryresistance to peel and shear stresses at elevated temperatures. It alsoimparted phase resistance to neoprene adhesives compounded therefrom.

EXAMPLE 2

This adhesive formulation was prepared to evaluate the product ofexample 1.

                  Part A                                                          ______________________________________                                        Neoprene AC           100     parts                                           Zinc Oxide            5        "                                              Magnesium Oxide       4        "                                              Zalba Special         2        "                                              ______________________________________                                    

The above ingredients were mixed on a cold roll mill, then thecompounded elastomer was cut into chunks and dissolved in 333 parts oftoluene.

                  Part B                                                          ______________________________________                                        Resin produced in example 1                                                                         45.0    parts                                           Magnesium Oxide       4.5      "                                              Water                 2.0      "                                              Toluene               47.5     "                                              ______________________________________                                    

The above ingredients were placed in a pint can and rolled overnight atroom temperature to prereact the resin.

Parts A and B were then blended together to form the finished adhesivecomposition.

The adhesive was then tested for shear strength when bonding cotton duckto an alkyd painted panel. The shear strength was tested at roomtemperature, 158° F. and 250° F.

Below are recorded the maximum shear values obtained, along with acontrol adhesive which contains SP-134, a conventional heat reactivephenolic resin made from p-t-butylphenol, Bisphenol A and formaldehyde(M.P. Cap.=160° F.) compounded exactly as the above adhesive.

    ______________________________________                                                                   Resin of                                                        SP-134.       Example 1,                                         Condition    psi           psi                                                ______________________________________                                        Room Temp    105           115                                                158° F.                                                                             45            54                                                 250° F.                                                                             12            49                                                 ______________________________________                                    

EXAMPLE 3

A mixture of xylene 900 g., Bisphenol A 15.6 g., p-phenyl-phenol 283 g.,p-t-butylphenol 500 g., 37% formaldehyde 480 g. and methanol 50 g. wasbrought to 55° C. Then 75 g. of 50% sodium hydroxide was added. Thetemperature was brought to reflux and held for 1/2 hour. The batch wasthen neutralized with 168 g. 20% hydrochloric acid. The resin was thenwashed twice with water as in example 1.

Three grams of 85% phosphoric acid, and three hundred grams of woodrosin were added and the mixture was heated to 150° C. whileatmospherically distilling off volatiles. Zinc resinate 114 g. was thenadded and the mixture was brought to 190° C. held 1/2 hour, then pouredinto a pan to cool, yielding 1269 g. of a homogeneous resin. M.P.Cap.=300° F.

EXAMPLE 4

A mixture of 300 g. of xylene, 5.2 g. of Bisphenol A, 94 g. ofp-phenylphenol, 166 g. of p-t-butylphenol, 160 g. of 37% uninhibitedformaldehyde, 107 g. of wood rosin and 38 g. of zinc resinate was heatedto 60° C. At this temperature 8 grams of 50% sodium hydroxide wereadded.

The temperature was brought to reflux and held for approximately 3hours. The resin was then distilled to 191° C. and poured into a pan tocool, yielding 427 g. of a resin melting at 280° F.

EXAMPLE 5

A mixture of 300 g. of xylene, 5.6 g. of Bisphenol A, 118 g. of alphamethylstyryl phenol, 166 g. of p-t-butylphenol, 16 g. of methanol, 140g. of 37% formaldehyde was heated to 55° C. 27 g. of 50% aqueous sodiumhydroxide was added and the mixture was heated to reflux. The reactionwas maintained at reflux for 40 minutes. The resin was then neutralized,with 59.4 gms. of 20% hydrochloric acid. The resin was then washed twicewith water. Eighty grams of wood rosin was then added and the mixtureheated to 150° C. under atmospheric distillation. Thirty-eight grams ofZinc Resinate (Unirez 1028) was added and heating was continued to 190°C. The resin was then poured into a pan to cool. Yield=410 g. MeltingPoint (Cap)=260° F.

EXAMPLE 6

A mixture of 300 g. of xylene, 5 g. of Bisphenol A, 70 g. ofp-chlorophenol, 166 g. of p-t-butylphenol, 13 g. of methanol, 160 g. of37% uninhibited formaldehye was heated to 55° C., then 25 g. of 50%sodium hydroxide was added. The temperature was brought to reflux andheld at this temperature for 50 minutes. The mixture was neutralizedwith 77 g. of 20% hydrochloric acid. The resin was then washed twicewith water. One gram of 85% phosphoric acid and 90 g. of wood rosin wereadded and the temperature was brought to 156° C. Thirty-eight g. of zincresinate was then added and the temperature was brought to 205° C. Theresin was then poured into a pan to cool. Yield=379 g. Melting Point(Cap)=304° F.

EXAMPLE 7

A mixture of 300 g. of xylene, 94 g. of p-phenyl-phenol, 166 g. ofp-t-butylphenol, 13 g. of methanol, 160 g. of 37% formaldehyde washeated to 55° C. then 25 g. of sodium hydroxide was added. Thetemperature was brought to reflux and held for 38 minutes. The reactionproduct was then neutralized with 78.1 g. of 20% hydrochloric acid. Theresin was then washed twice with water.

One gram of 85% phosphoric acid and 107 g. wood rosin was added and themixture was distilled to 150° C. Thirty-eight g. of Unirez 1028 (ZincResinate) was added and the reaction was continued to 205° C. The resinwas then poured into a pan to cool. Yield=417 g., M.P. (Cap)=308° F.

EXAMPLE 8

A mixture of 900 g. of xylene, 15.6 g. of Bisphenol A, 283 g. ofp-phenylphenol, 500 g. of p-t-butylphenol, 50 g. of methanol, 496 g. of37% formaldehyde was heated to 55° C. then 75 g. of 50% sodium hydroxidewas added and the mixture was brought to reflux. Reflux was held for 45minutes. The mixture was then neutralized with 184 g. of 20%hydrochloric acid. The resin was washed twice with water. Nine g. of 85%phosphoric acid was added and heat was applied to 144° C. underdistillation conditions. Zinc Resinate (Unirez 1014), 114 g. was addedand distillation was continued to 187° C. The resin was then poured intoa pan to cool. Yield=1047 g. M.P.(Cap)=290° F.

The resins set forth in examples 3-8 were employed in place of the resinof example 1 in the adhesive formula of example 2 with the followingresults in the shear strength test.

    ______________________________________                                                        250° F. Shear                                          Example         Strength                                                      ______________________________________                                        3               57 psi                                                        4               63 psi                                                        5               34 psi                                                        6               35 psi                                                        7               53 psi                                                        8               59 psi                                                        ______________________________________                                    

It can be seen that the resins of the present invention are muchsuperior in their ability to promote elevated temperature adhesion inpolychloroprene adhesives than conventional adhesive resins such as SP-134.

EXAMPLE 9

To show that a simple mixture of zinc resinate and alkylphenoformaldehyde resin did not exhibit the high temperature adhesionexhibited by the resins of the present invention in chloropreneadhesives the following experiment was carried out.

A mixture of xylene 900 g. Bisphenol A, 15.6 g., p-phenylphenol 283 g.,p-t-butylphenol, 500 g., methanol 50 g. 37% uninhibited formaldehyde,480 g. was heated to 52° C., then 75 g. of 50% sodium hydroxide wasadded. The temperature was brought to reflux. The temperature was heldfor approximately one hour. The resin was then neutralized with 187 g.of 20% hydrochloric acid. The resin was washed twice. Four g. of 85%phosphoric acid was added. The temperature was then brought to 165° C.and the resin was poured into a pan to cool. Yield=1330 g., M.P.(Cap)=200° F.

The following pulverized mixtures were prepared by grinding in a mortar:

    ______________________________________                                        Component    9(a)     9(b)     9(c)   9(d)                                    ______________________________________                                        Unirez 1028   0 parts  14 parts                                                                               0 parts                                                                              10 parts                               Wood rosin    0  "     28  "    28 "   0 "                                    Resin of Example 9                                                                         100 "    100 "    100 "  100 "                                   ______________________________________                                    

Each of the formulations of examples 9(a), 9(b), 9(c), and 9(d) wasemployed in the place of the resin of example 1 in the adhesive ofexample 2 with the following results in the shear strength test.

    ______________________________________                                                        250° F. Shear                                          Example         Strength                                                      ______________________________________                                        9(a)            12 psi                                                        9(b)            22 psi                                                        9(c)             8 psi                                                        9(d)            10 psi                                                        ______________________________________                                    

It will be observed that the 250° F. adhesion values are very poorcompared to the reacted materials employed in the present invention.

EXAMPLE 10

900 grams of xylene, 283 grams (1.66 moles) of p-phenylphenol, 15.6grams (0.066 mole or 0.132 equivalent) of Bisphenol A, 500 grams (3.33mole) of p-t-butylphenol, 50 grams of methanol and 165 grams (2 moles)of 37% aqueous formaldehyde were loaded into a 5 liter flask set up forreflux. At 50° C. 25 grams of 50% aqueous sodium hydroxide were added,the temperature was then brought to reflux and held for 30 minutes. Then350 grams of water were added and next 50 ml. of 20% aqueous HCl toneutralize the sodium hydroxide. The batch was brought to 80° C. and 900grams of Unirez 1028 added. The resin was then distilled at 23 inches ofvacuum to 190° C. and poured. The yield was 1686 grams, M.P. (Capillary)170° F.

EXAMPLE 11

900 grams of xylene, 283 grams of p-phenylphenol, 15.6 grams ofBisphenol A, 500 grams of p-t-butylphenol, 50 grams of methanol and 331grams (4.0 moles) of 37% aqueous formaldehyde were loaded into a 5 literflask set up for reflux. At 45° C. 25 grams of 50% aqueous sodiumhydroxide were added, the temperature was then brought to reflux andheld for 10 minutes. Then 350 grams of water were added as well as 50ml. of 20% aqueous HCl. The resin was allowed to settle, the water layersiphoned off and 2100 grams of Unirez 1028 were added at 140° C. duringan atmospheric distillation. The temperature was brought to 180° C. andthen 20 inches of vacuum was applied and distillation was continued to210° C. The resin was then poured into a pan to cool. The yield was 2826grams, M.P. (Capillary) 250° F.

EXAMPLE 12

The resins prepared in examples 10 and 11 were employed in place of theresin of example 1 and the neoprene adhesive formula of example 2 withthe following results in the shear strength test.

    ______________________________________                                                        250° F. Shear                                          Example         Strength                                                      ______________________________________                                        10              28 psi                                                        11              35 psi                                                        ______________________________________                                    

Thus they had shear strength properties similar to those of examples 5and 6 and were superior to the conventional adhesive resins such asSP-134.

EXAMPLES 13-16

The formulations employed were as follows. The amounts were in grams.

    ______________________________________                                                       Examples                                                       Formulation      13      14      15    16                                     ______________________________________                                        A   Xylene           900     900   900   900                                  B   p-phenylphenol   283     283   283   283                                  C   p-t-butylphenol  500     500   500   500                                  D   Bisphenol A      15.6    15.6  15.6  15.6                                 E   Methanol         50      50    50    50                                   F   37% formaldehyde 415     415   415   365                                  G   50% sodium hydroxide                                                                           75      75    75    75                                   H   Water            350     350   350   350                                  I   20% hydrochloric acid                                                                          170     170   170   170                                  J   Water            500     500   500   500                                  K   Water            500     500   500   500                                  L   85% H.sub.3 PO.sub.4                                                                           3.0     3.0   3.0   3.0                                  M   Zinc Salicylate  75                                                       M   Zinc Borate              126                                              M   Zinc Phosphate                 42                                         M   Zinc Oxide                           15                                   ______________________________________                                    

Procedure

Materials A-F were loaded into a 5 liter flask set up for reflux. Thetemperature was brought to 50° C. Then G was added and the temperaturebrought to reflux and held for one hour. The batch was cooled to 80° C.and acidified with 1 to a pH of 3.0. The mixture was agitated for 0.5hour and the two layers were allowed to separate. The aqueous phase wasdecanted. The resin phase was washed first with J and then with K.Material L was added and the resin was distilled to 150° C. Material Mwas then added and distillation was continued to the followingtemperatures. The resins were then poured into a pan to cool.

    ______________________________________                                        Example          13      14      15    16                                     ______________________________________                                        Final Distillation Temperature                                                                 210° C                                                                         200° C                                                                         215° C                                                                       290° C                          Melting Point (Capillary)                                                                      320° F.                                                                        290° F.                                                                        280° F.                                                                      278° F.                         ______________________________________                                    

EXAMPLE 17

The resins prepared in examples 13-16 were employed in place of theresin of example 1 in the neoprene adhesive formula of example 2 withthe following results in the shear strength test.

    ______________________________________                                                        250° F.                                                                Shear                                                         Example         Strength                                                      ______________________________________                                        13              59 psi                                                        14              21 psi                                                        15              33 psi                                                        16              32 psi                                                        ______________________________________                                    

EXAMPLE 18

This example illustrates the use of another zinc compound to replacezinc resinate.

    ______________________________________                                        Formulation            Amount                                                 ______________________________________                                        A      Xylene              900 grams                                          B      p-phenylphenol      283 g.                                             C      Bisphenol A         15.6 g.                                            D      Methanol            50 g.                                              E      p-t-butylphenol     500 g.                                             F      37% formaldehyde    480 g.                                             G      50% sodium hydroxide                                                                              75 g.                                              H      Water               350 g.                                             I      20% HCl             155 ml.                                            J      Water               500 g.                                             K      Water               500 g.                                             L      85% H.sub.3 PO.sub.4                                                                              3 g.                                               M      Wood Rosin          321 g.                                             N      Zinc carbonate (basic)                                                                            321 g.                                                    (ZnCO.sub.3 Zn(OH).sub.2)                                              ______________________________________                                    

Materials A-F were loaded into a 5 liter flask set up for reflux. Thetemperature was brought to 50° C. and G was added. The temperature wasbrought to reflux and held for 0.5 hour. Material H and I were added andthe temperature then brought to 80° C. The mixture was agitated for 0.5hour and then the aqueous phase was decanted. The resin solution waswashed first with material J and then with material K. The resin wasthen acidified with L and M was added. The resin was distilledatmospherically to 140° C. and then N was added and distillation wascontinued to 220° C. and held for 20 minutes.

The batch was then poured into a pan to cool. The product had a meltingpoint (capillary) of 290° F. and a molecular weight of 1155. In theshear strength test at 250° F. in the neoprene formulation of example 2the adhesive had a 36 psi tensile shear value. This was much superior toa conventional phenolic heat reactive resin which usually runs about 10psi.

.Iadd.In the examples the molar ratios of formaldehyde to moles of totalphenol in the example are as follows:

    ______________________________________                                        Example    Formaldehyde:Phenol Mole Ratio                                     ______________________________________                                        1          1.29:1                                                             2          Same as Example 1                                                  3          1.16:1                                                             4          1.19:1                                                             5          1.03:1                                                             6          1.18:1                                                             7          1.20:1                                                             8          1.21:1                                                             9          1.17:1 (comparative example)                                       10         0.395:1                                                            11         0.795:1                                                            12         Uses the products of Examples 10 and 11.                           13         1.02:1                                                             14         1.02:1                                                             15         1.02:1                                                             16         0.89:1                                                             17         Uses the Products of Examples 13-16.                               18         1.17:1                                                             ______________________________________                                    

Thus in the examples the molar ratio of formaldehyde to phenol rangesfrom 0.395:1 to 1.29:1. .Iaddend.

We claim: .[.1. An adhesive composition comprising a polymer of chloroprene and the heat reaction product of zinc resinate and an alkaline condensed alkyl or aryl substituted phenolformaldehyde resin..]. .[.2. An adhesive composition according to claim 1 wherein the phenol is para alkyl substituted phenol..]. .[.3. An adhesive composition according to claim 2 wherein the alkyl group has 3 to 6 carbon atoms..]. .[.4. An adhesive composition according to claim 1 comprising 100 parts of the chloroprene polymer and 5 to 200 parts of the zinc resinate reacted phenol formaldehyde resin..]. .[.5. An adhesive composition according to claim 4 wherein the phenol formaldehyde resin contains at least 0.7 mole of formaldehyde per mole of phenol and the zinc resinate is used in an amount of 5 to 35% based on the final resin..]. .[.6. An adhesive composition according to claim 5 wherein the phenol formaldehyde resin is a para alkylphenol formaldehyde resin having a part of the alkylphenol replaced by a member of the group consisting of arylphenols, chlorophenol and 2,2-bis-4'-hydroxyphenol) propane wherein the heat reaction in preparing the zinc resinate-phenol formaldehyde product was terminated at a temperature between 150° C. and 250° C..]. .[.7. An adhesive composition according to claim 6 including rosin..]. .[.8. An adhesive composition according to claim 5 wherein the phenol formaldehyde resin contains at least 0.3 mole of formaldehyde per mole of phenol and the zinc resinate is used in an amount of 5 to 75% based on the final resin..]. .[.9. An adhesive composition according to claim 8 wherein the phenol formaldehyde resin is a p-alkylphenol formaldehyde resin having 2 to 70% of the alkylphenol replaced by a member of the group consisting of arylphenols, chlorophenol and 2,2-bis-(4'-hydroxyphenyl) propane and wherein the heat reaction in preparing the zinc resinate-phenol formaldehyde product was terminated at a temperature between 150° C. and 300° C..]. .[.10. An adhesive composition according to claim 9 including rosin..]. .[.11. An adhesive composition comprising a polymer of chloroprene and the heat reaction product of a zinc compound selected from the group consisting of zinc resinate, zinc oxide, zinc carbonate, zinc borate, zinc salicylate and zinc phosphate, and an alkaline condensate alkyl or aryl substituted phenol-formaldehyde resin..]. .[.12. An adhesive composition according to claim 11 wherein the zinc compound is a zinc compound other than zinc resinate..].
 13. An adhesive composition according to claim .[.11.]. .Iadd.20 .Iaddend.wherein the zinc compound is selected from the group consisting of .[.zinc oxide,.]. zinc borate, zinc phosphate, zinc salicylate and basic zinc carbonate.
 14. An adhesive composition according to claim .[.11.]. .Iadd.20 .Iaddend.wherein the phenol is a para alkyl phenol.
 15. An adhesive composition according to claim 14 wherein the alkyl group has 3 to 6 carbon atoms.
 16. An adhesive composition according to claim .[.11.]. .Iadd.20 .Iaddend.comprising 100 parts of the chloroprene polymer and 5 to 200 parts of the zinc compound reacted phenol-formaldehyde resin.
 17. An adhesive composition according to claim 16 wherein .[.the phenol formaldehyde resin contains at least 0.3 mole of formaldehyde per mole of phenol and.]. the zinc compound is used in an amount of .[.0.5.]. .Iadd.5 .Iaddend.to 75% based on the final resin.
 18. An adhesive composition according to claim 17 wherein the zinc compound is selected from the group consisting of .[.zinc oxide,.]. zinc borate, zinc phosphate, zinc salicylate and zinc carbonate.
 19. A composition according to claim 18 including rosin in an amount of 20 to 45% of the phenols employed. .Iadd.
 20. An adhesive composition comprising a polymer of chloroprene and the thermoplastic heat reaction product of a zinc compound selected from the group consisting of zinc carbonate, zinc borate, basic zinc carbonate, zinc salicylate and zinc phosphate, and an alkaline condensed alkyl or aryl substituted phenol-formaldehyde resin made by condensing formaldehyde and the phenol in a molar ratio of from 0.395:1 to 1.29:1. .Iaddend. .Iadd.
 21. An adhesive composition according to claim 20 wherein the zinc compound is selected from the group consisting of zinc carbonate, zinc borate, zinc salicylate and zinc phosphate. .Iaddend..Iadd.
 22. an adhesive composition according to claim 21 wherein the zinc compound is zinc carbonate. .Iaddend..Iadd.
 23. An adhesive composition according to claim 21 wherein the zinc compound is zinc borate. .Iaddend..Iadd.
 24. An adhesive composition according to claim 21 wherein the zinc compound is zinc salicylate. .Iaddend. .Iadd.
 25. An adhesive composition according to claim 21 wherein the zinc compound is zinc phosphate. .Iaddend. 